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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KLWX 040843
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
343 AM EST TUE MAR 4 2014

.SYNOPSIS...

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COLD CANADIAN HIGH PRESSURE IS SETTLING OVER THE AREA TONIGHT
BRINGING MUCH COLDER THAN NORMAL TEMPERATURES. THE HIGH WILL
REMAIN OVER THE REGION THROUGH WEDNESDAY. LOW PRESSURE IS EXPECTED
TO DEVELOP NEAR THE SOUTHEAST COAST MIDWEEK AND TRACK UP OR JUST
OFF THE EASTERN SEABOARD LATE IN THE WEEK.
-- End Changed Discussion --

&&

.NEAR TERM /TODAY/...

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WOW. I WENT TO COLLEGE IN NORTHERN VT - JUST S OF THE CANADIAN
BORDER. RARELY DOES WINTER WX OF THE MID ATLC REMIND ME OF NRN
NEW ENGLAND...BUT TNGT IS ONE SUCH NGT. TEMPS HOVERING ARND ZERO.
DRIVING IN I SAW A PHENOMENON I ALSO RARELY SEE HERE - "ARCTIC SEA
SMOKE." WHILE DRIVING OVR A CREEK THERE WAS A HZ/FG ON EITHER
SIDE. THIS IS THE RESULT OF THE RLTVLY "WARM" WATER - IN THIS CASE
ABV FRZG...AND THE 30 DEG COLDER AIR ABV IT. HENCE THE WARMER AND
MOIST AIR ABV THE CRK WAS CONDENSING AS SOON AS IT ENCOUNTERED THE
ZERO DEG AIR...CREATING A SHALLOW LOW-LYING FOG LYR. SOMETHING
MORE LKLY SEEN IN NORWAY THAN THE MID ALTC.

LOW TEMP RECORDS FOR TDA HV ALREADY FALLEN...OR ARE IN JEOPARDY OF
FALLING. THE RECORD FOR IAD FOR 3/4 IS 6 SET IN 1980. BWI`S...
WHICH IS THE OFFICAL OBSERVING SITE FOR BALT...IS 5 SET OVR 140
YRS AGO IN 1873. THE 2 AND 3 AM OBS SHOW THE IAD TEMP IS
ZERO...BWI`S IS 6. ONE THING - WHEN IT IS THIS COLD...AND WINDS
ARE CALM...IT IS PSBL TO HV A WIDE VARIANCE IN TEMPS OVR A SMALL
AREA BASED ON TOPOGRAPHY/LANDSCAPE.

FOR TDA THE CANADIAN HIGH WL BE SITUATED OVR THE RGN. ONLY CLDS
XPCTD TO BE SEEN TDA WL BE OFF THE HIGH VARIETY WHICH WL ALLOW
INSOLATION TO REACH THE SFC ALONG W/ SOME WRMG. HIGH TEMPS TDA WL
STILL BE SOME 20 DEGS BLO NRML...BUT WE ARE JUST A LTL OVR 2 WKS
FM THE EQUINOX...SO THE SUN ANGLE IS INCRSG.

HIGHS IN THE U20S/L30S.
-- End Changed Discussion --

&&

.SHORT TERM /TONIGHT/...

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HIGH PRES CONTS OVR THE AREA TNGT. TEMPS WON`T BE AS COLD AS THE
PRSNT NGT...BUT STILL WELL BLO NRML. IN MOST PLACES LOWS SHOULD
DROP TO LM TEENS...SINGLE DIGITS IN THE HIGHLANDS...U TEENS/20S IN
THE CITIES.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...

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AFTER A FEW INCHES OF SNOW ACROSS MUCH OF THE AREA ON MONDAY...WILL
ASSUME THAT MUCH OF IT WILL STILL BE AROUND ON WED - AT LEAST ENOUGH
TO DROP TEMPS A COUPLE OF DEG AT LEAST. A 1040MB HIGH PRESSURE
CENTER OVER ONTARIO/QUEBEC WILL STEER SOME LIGHT BUT COOL AIR DOWN
THE I-95 CORRIDOR FROM NEW ENGLAND. AFTER ANOTHER COLD OVERNIGHT W/
LOWS IN THE TEENS TONIGHT...TEMPS WILL CLIMB INTO THE 30S WED AFTN
BUT TEMPS IN THE M-U30S STILL AROUND 10-15 DEG BELOW AVG. STILL A
GOOD DAY FOR SNOW/ICE MELTING AT LEAST FOR A BETTER PART OF THE
DAYTIME HRS - OR UNTIL MID LEVEL CLOUDS MOVE IN LATER IN THE DAY.

DEWPOINTS WILL BE HIGHER WED NIGHT WHICH WILL HELP CAP THE OVERNIGHT
LOWS FROM DROPPING MUCH BELOW THE 20 DEG MARK. MEANWHILE...A FEW
WEAK UPPER LEVEL FEATURES WILL BE APPROACHING MULTIPLE AREAS - FROM
THE NW TO THE SW. HEADING INTO THE DAYTIME HRS THU...YET ANOTHER
STORM SYSTEM WILL BE DEVELOPING OVER THE DEEP SOUTH. THIS
SYSTEM...INITIALLY A CLUSTER OF POORLY ORGANIZED SHOWERS OVER THE
GULF COAST THAT GET A BOOST FROM A SPLIT-OFF UPPER VORT LOBE WELL
SOUTH OF THE MAIN UPPER JET STREAM REGION. LATE WED INTO THU...THIS
FEATURE WILL THEN DIP DOWN INTO THE LOWER MS VLY...SCOOP UP SOME
MOISTURE AND CONTINUE TO PUSH ACROSS THE DEEP SOUTH.

THIS FEATURE SOUTHEAST STORM SYSTEM IS SHOWN AS A FAIRLY POTENT
VORT MAX BY BOTH THE 00Z EURO AND GFS RUNS. THE EURO TENDS TO
BUILD A BIT MORE OF A SERN ATLC MOISTURE FETCH AND A MORE
AGGRESSIVE LOOK ONE IT REACHES THE SRN APLCNS...GA/SC LATE THU
NIGHT. A COUPLE OF OTHERS FEATURES WILL BE THE ONES TO WATCH
HOWEVER...AS THEY WILL LIKELY INFLUENCE THE MOVEMENT THE SOUTHEAST
SYSTEM. THE FIRST KICKER...A WEAK BUT FAST-MOVING CLIPPER N OF THE
GREAT LAKES THAT SHOULD AT LEAST VERY LEAST BUT A NRN "LID" TO THE
SOUTHEAST SYSTEM AND PREVENT SOME OF THE TYPICAL NWD MOVEMENT. THE
SECOND KICKER IS ANOTHER CUT-OFF LOW - THIS ONE OVER THE SRN
ROCKIES/DESERT SW THAT LOOKS TO DIVE EVEN FURTHER SOUTH AND PUSH
THE SOUTHEAST SYSTEM STRAIGHT OFF THE COAST.

CURRENT MED RANGE GUIDANCE AND PREV TRENDS KEEP THE SRN FRINGE OF
THE CWA BEING CLIPPED NRN EXTENT OF THE PRECIP. THE PROXIMITY OF THE
PRECIP SHIELD...HOWEVER ORGANIZED OR DISORGANIZED AT THIS POINT -
STILL LEAVES ROOM FOR DIFFERING TRENDS IN THE COMING DAYS. KEPT A
LOW CHANCE POP FOR THE AREA DURING A PERIOD OVERNIGHT THU INTO EARLY
FRI. THE EURO KEEPS THE SYSTEM LAGGING BEHIND A BIT OVER THE
SOUTHEAST BEFORE MOVING OFF THE COAST...BUT STILL KEEPING THE PRECIP
LARGELY SOUTH AND EAST OF THE AREA ON FRI. THE BEST CHANCE FOR
WINTRY PRECIP W/ THIS SYSTEM WOULD BE OVERNIGHT ALSO...W/ HIGHS ON
THU IN THE M30S - LOWS IN THE 20S AND HIGHS CLIMBING BACK INTO THE
M40S ON FRI.

HIGH PRESSURE WILL THEN TAKE OVER INTO THE WEEKEND...W/ THE UPPER
LOW OVER THE DESERT SW DRIFTING INTO THE SRN PLAINS. THE HIGH WILL
BE ENOUGH TO BRING OUR TEMPS BACK INTO THE 50S ON SAT...OR AT LEAST
CLOSE TO AVG FOR THIS TIME OF YEAR. A COUPLE OF WEAK EMBEDDED
SHORTWAVES THEN MAY HAVE THE CHANCE TO SLIDE OVER THE
AREA...BRINGING LITTLE IF ANY PRECIP AND DOING LITTLE TO CUT INTO
THE WARMER TEMPS AS WE GET BACK INTO AVG RANGE FOR THE START OF NEXT
WEEK.
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&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...

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VFR CONDS TDA AND TNGT.

OUTSIDE OF A CLOSE PASSAGE OF A LOW PRESSURE SYSTEM TO OUR SOUTH
OVERNIGHT THU INTO EARLY FRI...NOT MANY SUBSTANTIAL WX FEATURES ARE
EXPECTED TO AFFECT THE REGION OVER THE NEXT FEW DAYS. STILL SOME
WIGGLE ROOM FOR MODELS TO BRING THIS SYSTEM CLOSER TO THE AREA...SO
THIS FEATURE WILL NEED TO BE MONITORED FOR DIFFERING TRENDS. TEMPS
WILL GRADUALLY IMPROVE INTO THE END OF THE WEEK. WINDS WILL BE
MAINLY LIGHT AND NOT MUCH PRECIP EXPECTED OVER THE NEXT FEW DAYS.
-- End Changed Discussion --

&&

.MARINE...

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SCA IN EFFECT FOR THE BAY AND LWR PTMC. WINDS ARE DIMINISHING.
THIS EXPIRES AT 6 AM.

HIGH PRESSURE WILL KEEP WINDS LIGHT AND VRB INTO MID WEEK...AS
ANOTHER STORM SYSTEM DEVELOPS OFF THE CAROLINA COAST FROM THU INTO
FRI. THIS FEATURE WILL DRIFT OFF THE COAST INTO FRI...BUT CLOSE
ENOUGH TO LAND TO DEVELOP PERIODS OF NEAR SCA GUSTS OVER THE WATERS
LATE THIS WEEK. MORE HIGH PRESSURE TO BUILD IN FOR THE WEEKEND.
-- End Changed Discussion --

&&

.CLIMATE...

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ON MON RECORD LOW TEMPS WERE SET AT IAD..MRB..AND BWI. IAD TIED
THEIR RECORD FOR SNOWFALL. AS MENTIONED ABV IAD HAS ALREADY SET A
LOW TEMP RECORD FOR THE 4TH...AND BWI HAS TIED A 141 YR OLD RECORD
W/ SVRL HRS OF NGT STILL TO GO.
-- End Changed Discussion --

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ531>534-537-539>543.
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&&

$$
PRODUCTS...WOODY!/GMS